1. Field of the Invention
The present invention relates to a bull nose clincher for use in connection with drywall corner connections. The bull nose clincher has particular utility in connection with crimping device for applying bull nose corners to dry wall corner connections.
2. Description of the Prior Art
Bull nose clinchers are desirable for fastening beads to drywall corners. A need was felt for a bull nose clincher that would apply a rounded surface corner instead of a square corner as is presently done.
The use of drywall corner connections is known in the prior art. For example, U.S. Pat. No. 5,333,483 to Smith discloses a Bull nose applicator for applying a bull nose to adjacent dry wall panels, the apparatus comprising an elongated channel member having a bull nose application surface defined by a central, partially curved portion intersected by a pair of mutually perpendicular flat side portions, the channel member including a pair of transversely disposed slots proximal to one end thereof in which a pair of opposed crimping members are situated and pivotally attached to the channel member for rotation between a first, stored position and a second, crimping position, the crimping members each including a specially configured cutting surface defined by a curved planform having a compound curvature which tapers to a knife edge along symmetrical radii in, the apparatus further including a linkage mechanism attached to the crimping members for reciprocating, the crimping members between the aforementioned first and second positions, respective, the linkage mechanism comprising a spring loaded anvil member which may be struck by a hammer or mallet, slidably disposed on an elongated rigid shaft attached to and extending outward from the channel member, and dual link pairs pivotally attached to the anvil member and the crimping members at opposite ends thereof, respectively. However, the Smith '483 patent does not have springs in each of the clamping members to individually squeeze a corner bead over an entire length.
Similarly, U.S. Pat. No. 4,670,957 to Wolford discloses a Tool for crimping a corner bead piece over an exterior plasterboard corner that has two faces substantially normal to one another across an interior corner, which fit then against and over a corner bead piece, which in turn is positioned against and over an exterior structural corner of meeting plasterboard sheets. A post extends rearwardly away from the faces, and a striker is mounted to move on the post. A crimping pin is carried relative to each face, connected at their remote ends to the striker, and connected relative to the frame by means of a shaft fitting through an angled slot in each crimping pin. As arranged, each crimping pin is operable to move from one axial position with a die end recessed behind the faces to another axial position with the die end projected forwardly beyond the faces. The crimping pins are angled relative to one another and relative to each respective tool face. Movement of each crimping pin from the recessed position to the projected position, causes the die end initially to just pass over the edge of the underlying corner bead piece and then to move laterally against the edge of the underlying corner bead piece. The striker is hit with a mallet to drive the crimping pins with enough force to crimp the corner bead piece to the structural corner. However, the Wolford '957 patent does not have springs in each of the clamping members to individually squeeze a corner bead over an entire length.
Lastly, U.S. Pat. No. 4,593,443 to Wolford discloses a Tool for crimping a corner bead piece over an exterior plasterboard corner that has two faces angled at a substantially right angle to one another across an interior corner, and a crimping pin is carried relative to each face operable to move from one position recessed behind the faces to another position projected forwardly beyond the faces. A post extends away from the corner rearwardly of the faces, and a striker is mounted to move on the post and is connected by linkage to the crimping pins. The tool fits with the faces over a corner bead piece, the piece itself being positioned over an exterior structural corner of meeting plasterboard sheets. The striker is adapted to be hit with a mallet or the like to drive the crimping pins from the recessed position to the projected position, and against the underlying corner bead piece and into the plasterboard, operable to crimp part of the corner bead piece into the plasterboard and secure it over the exterior plasterboard corner. The disclosed tool has magnet means carried on the tool faces, adapted to magnetically cooperate with and releasably hold the corner bead piece as positioned thereagainst. This allows one-hand manipulation of the tool and the corner bead piece as the corner bead piece is first being fitted over the exterior plasterboard corner and prior to crimping the piece with the tool. However, the Wolford '443 patent does not have springs in each of the clamping members to individually squeeze a corner bead over an entire length.
While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a bull nose clincher that allows crimping device for applying bull nose corners to dry wall corner connections. The Smith '483, Wolford '957 and Wolford '443 patents make no provision for springs in each of the clamping members to individually squeeze a corner bead over an entire length.
Therefore, a need exists for a new and improved bull nose clincher which can be used for crimping device for applying bull nose corners to dry wall corner connections. In this regard, the present invention substantially fulfills this need. In this respect, the bull nose clincher according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of crimping device for applying bull nose corners to dry wall corner connections.